Phototactic flying insects are not only unsightly and unpleasant, but cause problems in various industries. For example, incidents where products made in food factories are contaminated by flying insects, such as flies and mosquitoes, are major issues in terms of quality control for hygienic reasons. At suburban factories, agricultural pests, such as planthoppers (Delphacidae) and leafhoppers (Cicadellidae), may get trapped in products as a result of such pests being attracted by lamplight from surrounding paddies and fields and flying toward the factories. Flying insects may also fly toward suburban restaurants and all-night convenience stores and greatly impact the business thereof by giving customers an unpleasant impression. Flying insects are also problematic in medical facilities, such as hospitals, and homes/residences, and are not preferable for hygienic and aesthetic reasons. Further, countermeasures against pests such as flying insects are an important task in the cultivation of crops.
Flying insects have a positive phototaxis and respond strongly to UV rays, and are strongly attracted particularly to UV rays in the long-wavelength range from 340 nm to 400 nm. Thus, flying insects are attracted to light-emitting elements emitting UV rays in the long-wavelength range, such as fluorescent lamps, mercury lamps, and LED illumination.
As countermeasures against these flying insects, various insect-proofing films and insect-proofing covers have been proposed which block UV rays by including a UV absorber. Such insect-proofing films and insect-proofing covers are used by being bonded to light-emitting elements, such as fluorescent lamps, mercury lamps, and LED illumination, or by covering such light-emitting elements, or by being bonded to window panes, or being employed as agricultural films, with the aim of blocking UV rays attracting flying insects (Patent Literatures 1 and 2).
Such conventional insect-proofing films and insect-proofing covers, however, have an insufficient capability of blocking UV rays in the long-wavelength range from 340 nm to 400 nm, and have an insufficient effect of inhibiting the attraction of flying insects. Further, such films/covers also block rays in the visible range (from 450 nm to 500 nm), thus reducing the amount of visible rays of light and making the lighting dim and/or the color of the lighting unnatural; if such films/covers are bonded to window panes, transparency may be impaired and/or the intake of natural light may be hindered. In agricultural applications, it is necessary to take in natural light to cultivate crops successfully while blocking UV rays to prevent the attraction of flying pests. Thus, there has been a demand for improvement in these areas.